The chief justice of the United States, William Rehnquist, has died at the age of 80. For more than 30 years, Justice Rehnquist left his mark on the highest court in the land.

The chief justice died at his Washington-area home late Saturday, surrounded by his three children.

He had been battling thyroid cancer for almost a year, but continued to perform his duties on the court while receiving treatment. In July, he put out a statement saying he had no plans to retire. But his health declined rapidly in recent days, and while news of his death came as a bit of a surprise, it was not a shock.

President Bush was among the first to get the news, and is expected to make a personal statement after attending Sunday church services. Aides to the president say he was deeply saddened to learn of the death of the chief justice, and called it a tremendous loss for the nation.

William Rehnquist was appointed to the Supreme Court by President Richard Nixon in 1971 and took his seat in 1972. He was elevated to chief justice by President Ronald Reagan in 1986.

During his tenure, the court slowly moved in a more conservative direction. But he is likely to be most remembered for events that occurred in the later years of his life: the 1999 impeachment trial of President Bill Clinton and the 2000 ruling that helped decide a presidential election.

The chief justice, acting according to U.S. law, presided over the Clinton impeachment trial in the U.S. Senate. It was William Rehnquist who formally announced that the Senate had voted not guilty.

"Our work as a court of impeachment is done," he said. "I leave with the hope that our several paths may cross again under happier circumstances."

Almost two years later, the court helped decide just who would succeed Bill Clinton as president.

"We will hear argument now in number 00949, George W. Bush and Richard Cheney versus Albert Gore et al.," he said.

With the 2000 election results under challenge in the state of Florida, the Rehnquist supreme court turned down a request from Democratic candidate Al Gore to continue a recount. The court's ruling, in essence, declared Republican George W. Bush the victor.

The passing of William Rehnquist gives President Bush his second court opening in two months. Justice Sandra Day O'Connor announced her retirement on July 1 The president chose a former Rehnquist clerk and friend, Judge John Roberts, to replace her. Mr. Roberts' Senate confirmation hearings were scheduled to begin on Tuesday.